I just joined this forum for a little help. I have a 1998 Tacoma. I love this truck. I have had a check engine light on for months. I have received numerous error codes.
I have replaced the Front 02 sensor, replaced the Air Filter, Fuel Filter, cleaned the MAF Sensor, cleaned the throttle body, and changed the Coolant Temperature Sensor.
The latest error code was the coolant temp sensor. I replaced the Coolant Temperature Sensor yesterday and reset the light. The light came right back on. I had it checked again and received Error Code P0125 (closed loop fuel control insufficient coolant temperature. I used a meter to check the ohms on the 02 sensor and both front and rear read what my Chilton books say they should. My book also says to check at the engine side of the wire for voltage with the switch on. There is no voltage at the connector to both the 02 sensors. My book suggest checking the fuse but I have not been able to find the correct one. Does anyone have any idea.